Struct WpPresentationFeedback

pub struct WpPresentationFeedback { /* private fields */ }

Available on crate feature wayland and Linux only.

presentation time feedback event

A presentation_feedback object returns an indication that a wl_surface content update has become visible to the user. One object corresponds to one content update submission (wl_surface.commit). There are two possible outcomes: the content update is presented to the user, and a presentation timestamp delivered; or, the user did not see the content update because it was superseded or its surface destroyed, and the content update is discarded.

Once a presentation_feedback object has delivered a ‘presented’ or ‘discarded’ event it is automatically destroyed.

This interface has no requests.

Implementations

impl WpPresentationFeedback

pub fn sync_output(&self, output: &WlOutput)

presentation synchronized to this output

As presentation can be synchronized to only one output at a time, this event tells which output it was. This event is only sent prior to the presented event.

As clients may bind to the same global wl_output multiple times, this event is sent for each bound instance that matches the synchronized output. If a client has not bound to the right wl_output global at all, this event is not sent.

pub fn presented( &self, tv_sec_hi: u32, tv_sec_lo: u32, tv_nsec: u32, refresh: u32, seq_hi: u32, seq_lo: u32, flags: Kind, )

the content update was displayed

The associated content update was displayed to the user at the indicated time (tv_sec_hi/lo, tv_nsec). For the interpretation of the timestamp, see presentation.clock_id event.

The timestamp corresponds to the time when the content update turned into light the first time on the surface’s main output. Compositors may approximate this from the framebuffer flip completion events from the system, and the latency of the physical display path if known.

This event is preceded by all related sync_output events telling which output’s refresh cycle the feedback corresponds to, i.e. the main output for the surface. Compositors are recommended to choose the output containing the largest part of the wl_surface, or keeping the output they previously chose. Having a stable presentation output association helps clients predict future output refreshes (vblank).

The ‘refresh’ argument gives the compositor’s prediction of how many nanoseconds after tv_sec, tv_nsec the very next output refresh may occur. This is to further aid clients in predicting future refreshes, i.e., estimating the timestamps targeting the next few vblanks. If such prediction cannot usefully be done, the argument is zero.

For version 2 and later, if the output does not have a constant refresh rate, explicit video mode switches excluded, then the refresh argument must be either an appropriate rate picked by the compositor (e.g. fastest rate), or 0 if no such rate exists. For version 1, if the output does not have a constant refresh rate, the refresh argument must be zero.

The 64-bit value combined from seq_hi and seq_lo is the value of the output’s vertical retrace counter when the content update was first scanned out to the display. This value must be compatible with the definition of MSC in GLX_OML_sync_control specification. Note, that if the display path has a non-zero latency, the time instant specified by this counter may differ from the timestamp’s.

If the output does not have a concept of vertical retrace or a refresh cycle, or the output device is self-refreshing without a way to query the refresh count, then the arguments seq_hi and seq_lo must be zero.

pub fn discarded(&self)

the content update was not displayed

The content update was never displayed to the user.

Trait Implementations

impl Borrow<ObjectId> for WpPresentationFeedback

fn borrow(&self) -> &ObjectId

Immutably borrows from an owned value.

impl Clone for WpPresentationFeedback

fn clone(&self) -> WpPresentationFeedback

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WpPresentationFeedback

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Hash for WpPresentationFeedback

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<Weak<WpPresentationFeedback>> for WpPresentationFeedback

fn eq(&self, other: &Weak<WpPresentationFeedback>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for WpPresentationFeedback

fn eq(&self, other: &WpPresentationFeedback) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Resource for WpPresentationFeedback

type Request = Request

The request enum for this interface

type Event<'event> = Event<'event>

The event enum for this interface

fn interface() -> &'static Interface

The interface description

fn id(&self) -> ObjectId

The ID of this object

fn version(&self) -> u32

The version of this object

fn data<U>(&self) -> Option<&U>

where U: 'static,

Access the user-data associated with this object

fn object_data(&self) -> Option<&Arc<dyn Any + Sync + Send>>

Access the raw data associated with this object.

fn handle(&self) -> &WeakHandle

Access the backend handle associated with this object

fn from_id( conn: &DisplayHandle, id: ObjectId, ) -> Result<WpPresentationFeedback, InvalidId>

Create an object resource from its ID

fn send_event( &self, evt: <WpPresentationFeedback as Resource>::Event<'_>, ) -> Result<(), InvalidId>

Send an event to this object

fn parse_request( conn: &DisplayHandle, msg: Message<ObjectId, OwnedFd>, ) -> Result<(WpPresentationFeedback, <WpPresentationFeedback as Resource>::Request), DispatchError>

Parse a event for this object

fn write_event<'a>( &self, conn: &DisplayHandle, msg: <WpPresentationFeedback as Resource>::Event<'a>, ) -> Result<Message<ObjectId, BorrowedFd<'a>>, InvalidId>

Serialize an event for this object

fn client(&self) -> Option<Client>

The client owning this object

fn is_alive(&self) -> bool

Checks if the Wayland object associated with this proxy is still alive

fn post_error(&self, code: impl Into<u32>, error: impl Into<String>)

Trigger a protocol error on this object

fn downgrade(&self) -> Weak<Self>

Creates a weak handle to this object

impl Eq for WpPresentationFeedback